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Please help! Last night I turned my thermidistat down from 75 to 73. The heat pump would only run a few minutes and the shut down. The fan and thermiistat said it was still running and calling for cooling. The compressor stays off for a few minutes and then starts up again. It did this all night and it took 7 hours to bring the temp down 2 degrees. The compressor must be kicking out on high or low pressure. I just had it serviced about 2 weeks ago. They cleaned it and checked the pressures etc. They added a bit of 410A. Any body any ideas?

It could be any of several dozen things, no way to tell from here. Call the service company back and have them recheck it. Very possibly you are correct and it is going off on hi pressure due to being overcharged when they added the gas and also very possible that has nothing to do with it.....only an onsite investigation will determine.

Why do techs insist on adding more gas to a unit when they check it out. If the unit was performing well before the PM why would someone think they needed more freon. I wish home owners would wise up to the fact that an AC unit is a closed system and providing there is no leaks they should never needed freon added to them. My question is was the unit cooling well before the PM and if so I would question why the company added more 410a.

Originally posted by Black Adder Why do techs insist on adding more gas to a unit when they check it out. If the unit was performing well before the PM why would someone think they needed more freon. I wish home owners would wise up to the fact that an AC unit is a closed system and providing there is no leaks they should never needed freon added to them. My question is was the unit cooling well before the PM and if so I would question why the company added more 410a.

Originally posted by Black Adder Why do techs insist on adding more gas to a unit when they check it out. If the unit was performing well before the PM why would someone think they needed more freon. I wish home owners would wise up to the fact that an AC unit is a closed system and providing there is no leaks they should never needed freon added to them. My question is was the unit cooling well before the PM and if so I would question why the company added more 410a.

I think the reason he put more 410A in the heat pump is, when he put the gauges on and looked at the chart that is attached to the ispection plate he deceided that it needed a bit of refridgerant, just a bit, he said. One of the problems I think is, it's best to check a heat pump out when its warmer out and when its in cooling mode, right? Unfortuneatly, it was still cool enough the heat pump was still in heating mode. Nevertheless, I agree he shouldn't have put any in if he wasn't sure. It ticks me off, bigtime, now its hot and humid and my heatpump isn't working right, and they can't come to service it right away as they are too busy, they say. The tech had an apprentice with him, I don't know if something got overlooked or they left a valve open or not, or if there is too much 410A in system.
Thanks for responding
Thorton

While you can charge a heatpump in heating mode, it is not a really good way to final adjust a charge. I will try to get it close in heating mode and then come back and check it again when it is warm enough for AC. There is no way I would add freon to a unit that is in heating mode unless I weigh the charge in right from scratch. Maybe your guys know a better way than I do to do it in heating mode, but I doubt it. I could see them charging the unit if they fixed something, but putting in 410a just for the heck of it does not make any sense.